Head Lifting at 1.8 bar of boost ~ 450hp
#4
Is head boss cracking a concern with the higher specified torque of the HB studs? I'm going to be installing mine soon and I'm nervous about taking them to 90ft-lb.... Supermiata was unfortunately not very helpful when I asked. Wondering if my understanding of fasteners is just lacking here, maybe forces are way different given the different stud material and dimensions? I'd like to avoid destroying a $2000 head before I even have the chance to fire the car up
#5
Is head boss cracking a concern with the higher specified torque of the HB studs? I'm going to be installing mine soon and I'm nervous about taking them to 90ft-lb.... Supermiata was unfortunately not very helpful when I asked. Wondering if my understanding of fasteners is just lacking here, maybe forces are way different given the different stud material and dimensions? I'd like to avoid destroying a $2000 head before I even have the chance to fire the car up
#8
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I'd encourage all of you to do some serious reading about the torque specs included with various aftermarket head studs sold for the Miata.
It shouldn't take much searching to find some real world experiences
It shouldn't take much searching to find some real world experiences
#9
One thing that WILL crack a block, it torquing studs down into the block.
You never torque a bare bolt right down into a blind hole, it acts like a screw jack and cast iron does not like being stretched.
Studs go in finger tight, or just nipped up, until the bottom of the thread in the block is reached.
Plonk on your head, and then torque down the nuts to the specified figure.
Top of the block is in compression, stud in tension, head in compression.
If anything does go pop, its going to be the stud.
You never torque a bare bolt right down into a blind hole, it acts like a screw jack and cast iron does not like being stretched.
Studs go in finger tight, or just nipped up, until the bottom of the thread in the block is reached.
Plonk on your head, and then torque down the nuts to the specified figure.
Top of the block is in compression, stud in tension, head in compression.
If anything does go pop, its going to be the stud.
#11
I've read quite a bit, and used that information the last time I installed ARP head studs. My question was specifically about the HB studs as what SuperMiata recommends is substantially different than what the popular consensus seems to be on head stud torque. I'm sure there are some gaps in my understanding of fasteners, and was wondering if there is something else going on with the HB studs that might lend itself to a 90ft-lb torque spec being safe in our application. Different thread design, ARP2000 vs 8740, etc.
#16
Might be worth a shot trying this https://www.summitracing.com/parts/s...da/model/miata . Supposedly it can deal with very minor head lift and maintain seal.
#17
Might be worth a shot trying this https://www.summitracing.com/parts/s...da/model/miata . Supposedly it can deal with very minor head lift and maintain seal.
#19
Block side of hg was fine
Head side of hg showed a different story.
#20
I've run the felpro mls gasket at low to mid 30s psi and beat on car regularly with no issues. I do intend to build another motor for nitrous use on top of that boost level and will be using those cut ring head gaskets along with half filling the block. Will see how the sce cut ring gaskets perform upcoming year. They are a little pricey though.